کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
187418 459643 2013 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Modulation of electrochemical hydrogen evolution rate by araliphatic thiol monolayers on gold
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
Modulation of electrochemical hydrogen evolution rate by araliphatic thiol monolayers on gold
چکیده انگلیسی

Electroreductive desorption of a highly ordered self-assembled monolayer (SAM) formed by the araliphatic thiol (4-(4-(4-pyridyl)phenyl)phenyl)methanethiol leads to a concurrent rapid hydrogen evolution reaction (HER). The desorption process and resulting interfacial structure were investigated by voltammetric techniques, in situ spectroscopic ellipsometry, and in situ vibrational sum-frequency-generation (SFG) spectroscopy. Voltammetric experiments on SAM-modified electrodes exhibit extraordinarily high peak currents, which differ between Au(1 1 1) and polycrystalline Au substrates. Association of reductive desorption with HER is shown to be the origin of the observed excess cathodic charges. The studied SAM preserves its two-dimensional order near Au surface throughout a fast voltammetric scan even when the vertex potential is set several hundred millivolt beyond the desorption potential. A model is developed for the explanation of the observed rapid HER involving ordering and pre-orientation of water present in the nanometer-sized reaction volume between desorbed SAM and the Au electrode, by the structurally extremely stable monolayer, leading to the observed catalysis of the HER.

Figure optionsDownload as PowerPoint slideHighlights
► Araliphatic SAM with extraordinary electrochemical stability.
► Enhancement of the hydrogen evolution after reductive SAM desorption.
► In situ real time sum frequency generation (SFG) spectroscopy.
► Relation between reductive SAM desorption and hydrogen evolution.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Electrochimica Acta - Volume 90, 15 February 2013, Pages 17–26
نویسندگان
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